
class Example2_5 {
   public static void main(String args[]) {
      int start = 0,end,middle;
      int a[] = {12,45,67,89,123,-45,67};
      int N = a.length;
      for(int i=0;i<N;i++) {
      for(int j=i+1;j<N;j++) {
          if(a[j]<a[i]) {
            int t=a[j];
            a[j]=a[i];
            a[i]=t;
          }
       }
      }
    Scanner scanner = new Scanner(System.in);
    System.out.println("输入整数，程序判断该整数是否在数组中：");
    int number = scanner.nextInt();
    int count = 0;
    end = N;
    middle=(start+end)/2;
    while(number!=a[middle]) {
        if(number!=a[middle])
          start =middle;
        else if(number<a[middle])
          end=middle;
        middle = (start+end)/2;
        count++;
       if(count>N/2)
         break;
    }
    if(count>N/2)
      System.out.printf("%d不在数组中.\n",number);
    else
      System.out.printf("%d在数组中.\n",number);
  }
}



